             (do-defaults expression model)))
      (filter not-fail?)
      (map (fn [final]
-            (log/info (str "final: " ((:morph-ps model) final)))
+            (log/trace (str "final: " ((:morph-ps model) final)))
             final)))))
 
 (defn generate

                                        
;; during generation, will not decend deeper than this when creating a tree:
;; TODO: should also be possible to override per-language.
(def ^:const max-total-depth 10)

;; use map or pmap.
(def ^:const mapfn map)

(defn comp-path-to-complements
  "return a lazy sequence of bolts for all possible complements that can be added to the end of the _path_ within _bolt_."
  [bolt path model depth max-depth]
  (log/trace (str "comp-path-to-complements:" depth "/" max-depth ":" ((:morph-ps model) bolt) "@" path))
  (let [spec (get-in bolt path)
        lexemes (shufflefn (get-lexemes model spec))
        bolts-at (if (< depth max-depth)
